1. Field of the Invention
The invention relates to an electrical circuit arrangement for electronically-coded locks.
2. Prior Art
A code controlled, one-knob, electro-door-opening installation is known (German AS No. 27 21 139 and AS No. 29 52 212). In such case the code signals are fed in with a bell button, whereby either the keyed-in pulses are counted simultaneously, or after pressing the bell button, a pulse generator is put in motion which, depending on the duration of the operation of the knob, releases a certain number of impulses. After releasing, waiting and renewed pressing down of the bell button, the next number is fed into the next storage. When all code numbers are selected correctly, then finally the last storage releases the voltage supply of the electric door opener contact for a limited period of time.
In the case of such installations, a simultaneous counting of the key operation or a return report is required, in which case the release impulses may be counted by a flashing light. The decoding, that is to say the feeding in of the code to be recognized, therefore requires concentrated attention in every case, whereby the return report will still have to be hidden from unauthorized persons in order not to reveal the code.
For suitcases and briefcases, mechanically codable lockings in the form of so-called number locks are known. As a rule, they have 4 to 6 ten-digit number plates, which have to be set in a predetermined or arbitrary sequence to a certain number. The direction of rotation may also be prescribed. In the case of such number locks, they have the disadvantage that the setting of the correct number is relatively cumbersome and requires sight contact.
Number locks with electronic codings are also known, where a key is assigned to each digit of, for example, a six-digit number. For the purpose of unlocking the lock, the keys must be operated in a predetermined sequence, i.e., by repeatedly pressing down each key, the code number assigned to each digit is selected. In the case of these locks, also the feeding in of the code to be recognized requires complete attention and sight contact is required.
The programming or setting of the code in the case of the known electronically coded locks is in most cases quite complicated and, therefore, will have been done already at the factory.